1.A 480 V three-phase blower motor with pilot lights and auxiliary contacts will not start because the push button is inactive due to a thermal overload condition. What is the most probable reason?
1.一台配有指示灯和辅助触点的 480 V 三相鼓风机电机无法启动,原因是热过载状况导致其启动按钮处于非激活状态。最可能的原因是什么?
2.How can the rotation of a 10 HP three-phase motor be reversed?
2.如何改变一台 10 HP 三相电机的旋转方向?
3.What is the correct way to check a GFCI device?
3.检查 GFCI(接地故障断路器)装?
4.If corrosion is found inside a main service panel, what action should be taken?
4.如果在主配电箱内部发现腐蚀现象,应采取什么措施?
5.When verifying GFCI tripping between a conductor and equipment ground, which tool should be used?
5.在验证 GFCI 装置在导线与设备接地之间是否能正常跳闸时,应使用哪种工具?
6.What device allows manual control of a circuit’s on/off state?
6.哪种装置允许对电路的通/断状态进行手动控制?
7.A fuse has opened in a 480 V three-phase blower motor system with indicators. What is the most likely issue?
7.在一个配有指示装置的 480 V 三相鼓风机电机系统中,某熔断器发生熔断(开路)。最可能的问题是什么?
8.A garage light installed by a homeowner burns extremely bright briefly and fails. What is the likely cause?
8.某房主自行安装的车库照明灯在点亮瞬间亮度极高,随后便烧毁失效。可能的原因是什么?
9.Power tools are tripping a temporary power station. What should the electrical subcontractor do first?
9.电动工具的使用导致临时电源站频繁跳闸。电气分包商首先应该做什么?
10.When a heater turns on in a home, some lights brighten while others dim. What could be wrong?
10.当家中开启加热器时,有些灯变亮,而另一些变暗。这可能出了什么问题?